Question

A pair of equations is shown below:

y = 8x − 9
y = 4x − 1

Part A: Explain how you will solve the pair of equations by substitution or elimination. Show all the steps and write the solution. (5 points)

Part B: If the two equations are graphed, at what point will the lines representing the two equations intersect? Explain your answer. (5 points)

Answer 1

@welshfella

Answer 2

i will fan and medal

Answer 3

hint:
you can solve using the elimination method

Answer 4

i put it in subtitution method but this is all i got: part A: im am using the substitution method.
both of these equations are solved for y.
im going to substitute the first equation into the second equation.
8x-9=4x-1.
im going to add 8x to both sides.
8x+8x-9=4x+8x-1.
16x-9=12x-1
add 9 to both sides.
16x=12.
divide both sides by 16.
16/12=

Answer 5

i dont know if im doing it right though

Answer 6

here is the first step:
\[\Large 8x - 9 = y = 4x - 1\]

Answer 7

ok. know i add 8 to both sides right?

Answer 8

we can add 9 to both sides, so we get:
\[\Large 8x = 4x - 1 + 9\]

Answer 9

ok. 8x=4x-10 right?

Answer 10

8x=4x+8

Answer 11

wait so the one is a negative? i have been getting confused with that. so what would be the next step?

Answer 12

next step:
we can subtract 4x at both sides, so we get:
\[\Large \begin{gathered}
8x - 4x = 8 \hfill \\
4x = 8 \hfill \\
\end{gathered} \]

Answer 13

ok. then we divide?

Answer 14

yes! we can divide both sides by 4